const NewsCate = require('./NewsCateModule');
const News = require('./NewsModule');
const Users = require('./UsersModule');


News.find().populate("cid").exec((err, docs) => {
    console.log(docs);
})
//populate查询是将 News中的外键ID 都查询出来的对象填充到这个ID地方,具体要查询那个外键(CID)定义